A separator original sheet used in a lithium-ion battery is slit (cut) in a machine direction of the original sheet, and thus a plurality of long separator sheets are obtained each of which has a predetermined width in a direction perpendicular to the machine direction. Each of the plurality of long separator sheets is wound on a core and is then supplied to a battery production process as a separator roll. In the battery production process, each of the plurality of long separator sheets is cut in a predetermined length in a direction perpendicular to the machine direction, and is thus used as a separator.
Patent Literature 1 discloses a method for storing and transporting long separator sheets which are obtained as above described.